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Abstract: A new phthalocyanine, tetra-{4-[5-(4-tert-butyl-phenyl)-[1,3,4]oxadiazol-2-yl]-phenoxy}-zincphthalocyanine (TOPc) was synthesized and its Langmuir–Blodgett (LB) film was fabricated and characterized by ultraviolet–visible (UV–vis) absorption and polarized UV–vis absorption spectra. The results show that the tilt angle of TOPc molecules on substrate is about 32°. Field-effect transistor incorporating with LB film of TOPc as a semiconductor layer was fabricated. A mobility of 1.1×10−4 cm2 V−1 s−1 and an on/off ratio up to 103 have been achieved. [Copyright &y& Elsevier]

Abstract: Four electroactive molecular materials with donor-π-acceptor-π-donor structures have been synthesized for investigation of structure–properties relationships, and used as dopant for electroluminescent applications. The optical and electrical properties of these materials are electronically manipulated by attaching different donors. The twisted intramolecular charge transfer (TICT) model is proposed by photophysical behaviors observed with increasing solvent polarity. Red electroluminescence devices were fabricated by spin coating the blend of polymer host and fluorescent guest. Highly efficient energy transfer leads to a saturated red emission with emission peak at 623nm, narrow bandwidth of 75nm and an external quantum efficiency of 0.38%. [Copyright &y& Elsevier]

Abstract: Two new linear divinylenes FN and PN that contained fluorene and phenylene, respectively, as central unit and naphthalimide terminal groups were synthesized by Heck coupling. In addition, two new star-shaped trivinylenes TPA-P and TPP-P that contained triphenylamine and 2,4,6-triphenylpyridine, respectively, as central core, and terminal phthalimide groups were similarly synthesized. All molecules were very soluble in common organic solvents due to their high fraction of aliphatic moieties which were attached to the central unit and/or the terminal imides. Trivinylenes showed higher thermal stability and higher glass transition temperature (118–126°C) than divinylenes. FN, PN and TPA-P emitted green-orange light with maximum at 518–586nm, while TPP-P emitted blue light with maximum at 444–462nm due to the kinked central core of 2,4,6-triphenylpyridine. The maximum luminance among the four molecules is 583cd/m2 at current density of 186mA/cm2 and applied voltage of 19.5V based on TPA-P, with a luminance efficiency maximum (η max) of 1.7cd/A. [Copyright &y& Elsevier]

Abstract: A new conjugated polymer, poly(3,6-dihexyl-thieno[3,2-b]thiophenyl-2,5-diyl-alt-2,5-di(2-ethylhexyl)-3,6-bis(thien-2,5-diyl)-pyrrolo[3,4-c]-pyrrole-1,4-dione) (DH-PTTDPP) was synthesized by Pd-catalyzed Stille-coupling method. The thermal, absorption, electrochemical, photovoltaic properties, and field-effect charge transport of the polymer were examined. The polymer is soluble in common organic solvents and possesses a broad absorption band covering from 500nm to 900nm with an optical bandgap of 1.33eV. Field-effect transistors (FETs) based on DH-PTTDPP thin film showed a hole mobility of 2.5×10−3 cm2 V−1 s−1 with an on/off ratio of 105, which is among the high values for the conjugated polymers. Polymer solar cells (PSCs) based on DH-PTTDPP/PC70BM (1:1.5, w/w) demonstrated a power conversion efficiency of 1.90% under the illumination of AM 1.5, 100mWcm−2. These results indicate that DH-PTTDPP is an attractive polymer semiconductor for the applications in FETs and PSCs. [Copyright &y& Elsevier]

Abstract: A new polythiophene derivative with octyloxyl triphenylamine-vinylene (OTPAV) conjugated side chain, OTPAV-PT, was synthesized according to the Stille coupling method, and characterized by 1H NMR, elemental analysis, GPC, TGA, UV–vis absorption spectroscopy, photoluminescence spectroscopy, and cyclic voltammetry. The polymer possesses excellent solubility in common organic solvents and good thermal stability with 5% weight loss temperature of 413°C. The weight-average molecular weight of OTPAV-PT was 1.04×104 with the polydispersity index of 1.45. Polymer solar cell with the configuration of ITO/PEDOT:PSS/OTPAV-PT:PCBM/Al was fabricated, and the power conversion efficiency of the device was 0.21% under the illumination of AM1.5, 100mW/cm2. The field effect hole mobility of the polymer reached 1.6×10−4 cm2 V−1 s−1. [Copyright &y& Elsevier]

Abstract: A series of blue-emitting materials with sp3 Si cores were synthesized by Suzuki Coupling reaction and characterized by spectroscopy. Their usages as blue emitters in organic light-emitting diodes (OLEDs) were preliminary investigated. Blue emission with comparable brightness and efficiency were obtained with structure of ITO/NPB/tetraarylsilane/TPBi/LiF/Al. Moreover, these tetraarylsilane compounds exhibited high thermal decomposition temperatures (T ds) which indicated that these compounds might be explored for potential application in flat panel display. [Copyright &y& Elsevier]

Abstract: Three new trimers PV, FV and CV were synthesized by Heck coupling of 4(4-bromophenyl)-2,6-diphenylpyridine with substituted divinylbenzene, divinylfluorene and divinylcarbazole, respectively. They were very soluble in chloroform, dichloromethane, tetrahydrofuran and toluene. FV and CV were more thermally stable and showed higher glass transition temperature than PV. Their absorption maximum was located at 327–397nm with optical band gap of 2.53–2.73eV. FV and CV emitted blue-green light with emission maximum at 455–489nm while PV emitted green-yellow light with emission maximum at 496–530nm. Upon protonation, the trimer thin films displayed red-shifts of the emission maximum. The electrochemical and electroluminescent properties of the trimers were studied. Light-emitting diodes (LEDs) based on these trimers were fabricated. These LEDs showed bright blue light for FV, CV and bluish-green light for PV which are in line with their photoluminescence spectra. The maximum brightness was reached approximate 1000cd/m2 for PV, 380 for FV, and 400 for CV, at current density of 200mA/cm2. [Copyright &y& Elsevier]

Abstract: A series of blue light-emitting compounds with different molecular shapes were synthesized by the Pd/Cu-catalyzed Sonogashira coupling reaction. These compounds composed of hole-transporting group (carbazole) and strong fluorescent group (pyrene), which linked through 9,9-dihexyl-2,7-fluorene ethynylene. The photoluminescent (PL) and electroluminescent (EL) behavior of these compounds was investigated. [Copyright &y& Elsevier]

Abstract: A carbazole compound was synthesized by Knovenagel condensation and characterized by the measurements of 1H NMR, IR and melting point. A multilayer organic light-emitting diode (OLED) using this compound as an active layer was fabricated by vacuum-deposition. This OLED showed a turn-on voltage of approximately 4.5V and a maximum luminance of 910cd/m2. Additionally, the maximum luminous efficiency was found as 0.95cd/A, at this point the device luminance was measured as 146cd/m2 at an operating voltage of 7V. The coordinate value of CIE 1931 was calculated as (x, y)=(0.3843, 0.5345) from the electroluminescence (EL) spectrum, which suggested that the device can emit a yellow-green light. [Copyright &y& Elsevier]

Abstract: A series of ethynyl-linked π-conjugated light-emitting molecules with good photoluminescence properties were designed and synthesized through Pd/Cu-catalyzed Sonogashira coupling reaction. The main structure comprised of different fluorophors (pyrene, carbazole, and fluorene), which were linked with triple bonds in order to be screened for high emission efficiency. Optical properties of these synthesized compounds (I a –I f ) were examined in solutions, thin films and solid states, respectively. All of them showed relative high quantum yields both in solutions (Φ s: 0.70–0.83) and in films (Φ f: 0.17–0.34). Light-emitting diode using I e as an emissive layer was fabricated in the ITO/poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS)/I e/2, 2′, 2″-(1, 3, 5)-benzene-triyl)tris[1-phenyl-1H-benzimidazole] (TPBI)/Al configuration. The maximum emission wavelength of the device was 496nm. The maximum luminance and electroluminescence efficiency was 1000cd/m2 and 0.41%, respectively. [Copyright &y& Elsevier]

Abstract: Two new light-emitting polymers, poly[2,2′-spirobifluorylene vinylene-alt-2,5-di-(n-buthoxy)-1,4-phenylene vinylene] (PSBF-PV) and poly[2,2′-spirobifluorylene vinylene-alt-9,9′-di-(fl-hexyl)-2,7-fluorenyl vinylene] (PSBF-FV) have been synthesized through the well-known Homer-Emons condensation between appropriate diphosphonates and dialdehydes. The polymers consist of arylenevinylene chromophores linked through 9,9′-spirobifiiorene to control the effective conjugation length and to suppress interchain aggregation. Photoluminescence maxima of PSBF-PV and PSBF-FV in thin solid film were shown at 512 and 446nm, corresponding to green and blue-green emission, respectively. The single-layer light-emitting diodes of the two copolymers were fabricated in the configuration of ITO (indium-tin oxide)/polymer/Al, exhibiting weak emission. Better performance (luminance maxima is 846cd/m2) was achieved using Alq3 as electron injection layer in double layer LEDs for PSBF-PV. [Copyright &y& Elsevier]

Abstract: Three novel phenyl-substituted poly(p-phenylene vinylene) (PPV) derivatives, BDP-PPV, BDMP-PPV, and BDP-co-BDMP-PPV (1:1), have been successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting polymers were characterized by using 1H, 13C NMR, elemental analysis, GPC, TGA, UV–vis absorption spectroscopy, photoluminescence (PL) and electroluminescence (EL) spectroscopy. The EL polymers possess excellent solubility in common solvents, good thermal stability with 5% weight loss temperature of more than 370°C, and higher photostability. The number-average molecular weight (M n) and polydispersity index (PDI) of the polymers were in the range of (1.52–2.53)×105 and 1.22–1.36, respectively. Double-layer light-emitting diodes (LEDs) with the configuration of ITO/polymer/Alq3/Al devices revealed that the copolymer, BDP-co-BDMP-PPV (1:1), possessed the highest luminescence properties, which exhibited maximum luminance of up to 3850cd/m2 at 23.5V, and maximum luminescence efficiency of up to 2.68cd/A. [Copyright &y& Elsevier]